[gtk/gtk-3-24: 1/2] Makefile.msvc_introspection: Delete lists before appending

[Christoph Reiter <creiter src gnome org>]

commit 6624f5f5a90a4c6a741a5e82079a0a02a89cae16
Author: Simon McVittie <smcv debian org>
Date:   Thu Jul 18 11:14:22 2019 +0100

    Makefile.msvc_introspection: Delete lists before appending
    
    Otherwise, we'll repeatedly append the same files to the list.
    
    Detected by running `make distcheck` twice in the same tree, with build
    system changes in between.
    
    Signed-off-by: Simon McVittie <smcv debian org>

 build/Makefile.msvc-introspection | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/build/Makefile.msvc-introspection b/build/Makefile.msvc-introspection
index 85c01b4dd9..afbf7c9cad 100644
--- a/build/Makefile.msvc-introspection
+++ b/build/Makefile.msvc-introspection
@@ -80,6 +80,7 @@ $(if $(or $(findstring --header-only,$($(_gir_name)_MSVC_SCANNERFLAGS)),
     $(error Need to define $(_gir_name)_MSVC_LIBS or $(_gir_name)_MSVC_PROGRAM))
 
 $(top_builddir)/build/win32/$(_gir_name)_list: Makefile
+       rm -f $(top_builddir)/build/win32/$(_gir_name)_list
        for F in $(_gir_files_msvc); do \
                case $$$$F in \
                *.c|*.cpp|*.cc|*.cxx|*.h|*.hpp|*.hh|*.hxx) \